Getting make to create object files in a specific directory

I solved this request and here is my Makefile and directory tree.

PROJECT := main.exe

DIR_SRC += .
DIR_SRC += ./src

DIR_INC += -lpthread 
DIR_INC += -I./inc 
DIR_INC += $(addprefix -I, $(DIR_SRC))

SRC_C += $(wildcard $(addsuffix /*.c, $(DIR_SRC)))
#OBJ := $(filter %.o, $(SRC_C:.c=.o))
OBJ := $(patsubst %.c, %.o, $(SRC_C))
EXE := $(PROJECT)

CC_PREFIX := 
CC := $(CC_PREFIX)gcc
CFLAG = 
CLIB = -L .

.PHONY:all

all:$(OBJ) $(EXE)

%.o: %.c
    $(CC) $(CFLAG) $(DIR_INC) -c $< -o $@ 

$(EXE): $(OBJ)
    $(CC) $(CFLAG) $(CLIB) $(OBJ) -o $@ 

clean:
    rm -r $(EXE) $(OBJ) 

See my directory tree:

You have two problems in this rule (well, three):

$(OBJECTS): $(SOURCES)
    $(CC) $(CFLAGS) -c $(SOURCES) $(LIB_PATH) $(LIBS)

You haven't noticed yet, but the rule makes each object dependent on all sources, and tries to build that way. Not a problem as long as you have only one source. Easy to fix with a static pattern rule and an automatic variable:

$(OBJECTS): src/%.o : src/%.c
    $(CC) $(CFLAGS) -c $< $(LIB_PATH) $(LIBS)

Also, the command ("$(CC)...") doesn't specify an output file name, so gcc will infer it from the source file name; if you give it src/timeout.c, it will produce timeout.o (in the working directory, project/). So you should specify the desired path to the output file. Easy to do with another automatic variable:

$(OBJECTS): src/%.o : src/%.c
    $(CC) $(CFLAGS) -c $< $(LIB_PATH) $(LIBS) -o $@

Use gcc's -o option to write the output file to a particular location. For instance, you could say:

$(CC) $(CFLAGS) -c $(SOURCES) $(LIB_PATH) $(LIBS) -o $(OBJECTS)

Unfortunately, there's a problem with this line: if there is more than one source file in $(SOURCES), it won't work, since $(OBJECTS) will also contain multiple file names, and the -o option only binds to the first argument.

A way to compile each file in a list of source code files is to use implicit rules. In gmake, you would write:

$(EXECUTABLE):  $(OBJECTS)
        $(CC) $(CFLAGS) -o $@ $(RUNTIME_PATH) $(OBJECTS) $(LIB_PATH) $(LIBS)

%.o : %.c
        $(CC) $(CFLAGS) -c $< -o $@

where $< is replaced with name of the input file and $@ is replaced with the name out the output file.